I do not specify version dependencies unless I happen to know (or to see from the CPAN pages) that there is a particular version that it will not work with. And, I concern myself with this only with code that I intend to distribute. Normally, I do control the installation of both the software that I have developed, and the packages that go with them, and both are installed from current sources at the same time.
I conscientiously avoid dependencies on “what is already installed,” e.g. at the hosting service. I supply everything that is needed, in the version that is known-good.